This invention relates generally to a means for preventing and stopping fluid passage through a fluid flow line, such as a gasoline line used in connection with a fuel dispensing system at a service station, as when the line is severed.
Particularly, a service station gas pump hose can be severed or ripped and a loss of fluid and vapors may be encountered, for example, when a driver of a vehicle drives off with the gasoline nozzle inadvertently remaining within the fuel tank of his automobile. This usually occurs in the self-service station. This invention is especially useful when applied in a fuel line functioning as a check valve to prevent fuel flow under particular adverse conditions.
There are an infinite number of valve means in the prior art that furnish shut-off of fluid flow, and more particularly, such mechanisms normally are utilized in fuel lines where fuel may be dispensed, and generally in those situations when the line comprises a fuel line leading from a gasoline dispenser to the nozzle. One example is U.S. Pat. No. 4,666,888 to the aforementioned Arthur Fink.
Another example can be seen in U.S. Pat. No. 2,642,297 to Hanna, which discloses a break-away coupling that responds to tension in the line which is mounted and is held together through a combination of male and female connectors and detents that provide bearing engagement between the two components. In addition, the U.S. Pat. Nos. 4,617,975 and 4,691,941 to Rabushka disclose various types of tension actuated couplers for the use in the line that deliver gasoline to a vehicle from a gas pump. The problems that have been encountered with the style of coupler as disclosed in these prior patents is that they have a tendency to leak. When internal pressure is exerted within the fuel line, such as may occur when the pumping of the gasoline is being performed, excessive pressures may build-up within the fuel line and particularly at the location of the uncoupler resulting in leakage. In some cases, the pressure, known as line shock, has the tendency to force the uncoupling device to prematurely come apart. This generally occurs in the type of break-away coupling that is constructed having unequal internal surfaces that cause greater fluid forces to be applied in one direction upon one part of the coupling than is exerted upon the other.
When spontaneous high pressures or line shocks are encountered, the pressure exerted upon one component of the coupling device in one direction, is substantially different from the fluid pressure that may be exerted in the other direction on the other component of the coupling device. This disparity in pressure has a tendency to force the coupler to prematurely separate, in an untimely and perhaps dangerous fashion. This can and has ocurred particularly where the fluid pressure generated within the hose may undertake a phenomenom that is equivalent to what is known in the art as "water hammer". Water Hammer is caused by the pumping of fuel through the flow line cresting pressure spikes that build up rather significantly and substantially, throughout the hose, momentarily when the flow is suddenly stopped. For example, when the fuel tank is full and the nozzle shut off, the spike in high pressure causes leakage in the couplers. This frequently occurs in the field, and, on occasion, as previously explained, untimely separation of the uncoupler has happened.
Another problem with the couplers known to the art is that they do not necessarily provide for a vapor passage wherein vapors are captured and returned to the system so as to prevent escape of vapors into the environment. Furthermore, those couplers known in the art and which do provide vapor passageways are usually external to the fluid flow path. They cannot be used on a concentric flow line wherein the vapor path in the line is internal to the fluid flow line.
Examples of other U.S. Patents that show various related uncoupling devices include U.S. Pat. No. 4,449,545, disclosing a poppet valve having a connical surface that is disposed for seating upon a valve seat, when breakage occurs between the various body components making up the plug and socket of the shown valve.
There are a great variety of other types of these hose couplers, employed in the art, as can be seen in U.S. Pat. No. 2,777,716 to Gray, showing a socket-type hose coupler with reciprocating detent. Another form of quick disconnect coupler and safety check valve is shown in U.S. Pat. No. 4,060,219, to Crawford.
In addition to the foregoing, the patent to Shames, U.S. Pat. No. 4,070,003, also discloses a coupler with automatic shut-off, but as can be seen, the sealing means provided therein is of substantial size and causes significant disruption to the normal flow of fluid through the coupler.
Another type of valve assembly is shown in U.S. Pat. No. 4,307,744 to Morrison. An additional form of break-away safety valve is shown in U.S. Pat. No. 4,064,889, to Gayle, wherein there is an incorporated ball valve which prevents the discharge of gasoline vapors in the event that a break occurs.
Other patents showing decoupling devices, for use in flow lines, of various types, are shown in U.S. Pat. No. 2,906,280 to Mount, entitled "Break-Away Coupling". U.S. Pat. No. 3,741,521 to Tatsuno shows a pipe coupling with safety valve. U.S. Pat. No. 1,410,218 to Pamer, discloses a gas valve. U.S. Pat. No. 2,777,716, to Gray discloses a socket-type hose coupler with reciprocating detent. U.S. Pat. No. 2,898,926 to Tsiguloff shows a safety disconnect valve for use in conjunction with fuel dispensing. U.S. Pat. No. 3,085,589 to Sands, discloses a safety valve. Another patent to Sands, U.S. Pat. No. 3,122,162, shows a flow control device. The patent to Shames, U.S. Pat. No. 4,070,003, shows a coupler with automatic shut-off. The patent to Allread, U.S. Pat. No. 4,119,111, discloses a frangible hose end fitting. The patent to Sands, U.S. Pat. No. 3,085,589 shows a safety valve. The patent to Johnson, U.S. Pat. No. 2,048,388, discloses another form of safety device, for use in conjunction with fuel dispensing. The patent to Scheiwer, U.S. Pat. No. 2,135,221, discloses a coupling used within a flow line. The patent to Clark, U.S. Pat. No. 2,452,430 shows another form of quick disconnect coupling. The patent to Yonkers, U.S. Pat. No. 2,455,544, shows a related type of pipe coupling. The patent to Scheiwer, U.S. Pat. No. 2,536,702, discloses a coupling for use within a flow line, and incorporating ball-type coupling members. Paskar, U.S. Pat. No. 2,599,935 discloses a hydraulic line coupling. Wurmser, U.S. Pat. No. 2,631,872, discloses a quick coupling device for flow lines. Clark, in his U.S. Pat. No. 2,860,893, shows a ball detent type coupling with break-away feature. Burning, U.S. Pat. No. 3,317,220, shows a resealable fluid coupling. Bolton, Jr., in U.S. Pat. No. 3,334,860, discloses a fluid coupling. Shendur, U.S. Pat. No. 3,715,099, discloses a valved quick-disconnect coupling. Silvana, U.S. Pat. No. 3,918,679, discloses a universal coupling. Taylor, in his U.S. Pat. No. 4,098,438, discloses a gasoline spill prevention system and apparatus. The patent to Morrison, U.S. Pat. No. 4,240,228, shows a pressure balanced fluid coupling. the patent to Parrish, U.S. Pat. No. 4,392,513, shows a quick disconnect safety coupling. The patent to Scheiwer, U.S. Pat. No. 2,536,702 discloses another form of coupling. A similar type of coupling assembly is shown in the patent Norton, et al, U.S. Pat. No. 3,836,114. Livingston, in U.S. Pat. No. 3,138,393, shows a coupling for substantially axialy fixed conduits. Burning, U.S. Pat. No. 3,317,220, shows a releasable fluid coupling. Wurmser in U.S. Pat. No. 2,631,872, discloses a quick coupling. Paskar, in U.S. Pat. No. 2,599,935, shows a hydraulic line coupling. Clark, et al in U.S. Pat. No. 2,452,430, shows a quick disconnect coupling. Clark, in U.S. Pat. No. 2,860,893, shows a ball detent type coupling with break-away features. Morrison, in U.S. Pat. No. 4,124,228, shows a pressure balance coupling.
These are examples of various prior art break-away coupling devices, primarily for use within a fluid flow line, and in certain instances are of the break-away type. None of the aforementioned, with the exception of U.S. Pat. No. 4,827,972, to Fink, a co-inventor of the present invention, discloses a break-away hose coupling that eliminates the effects of line shock or "water hammer".
Moreover, the couplings disclosed in the prior art show a vapor path internal of the fuel path. For example, in U.S. Pat. No. 4,827,977, to Fink, the break-away hose coupling is designed with a vapor path external to the fuel path.